1. Field of the Invention
The invention relates to a vehicular air conditioning device and a control method thereof.
2. Description of the Related Art
Conventionally, as an air conditioning device for regulating an air condition (a temperature, or the like) within a passenger compartment of a vehicle, or the like, air conditioning devices have been known such as those disclosed in, for example, Japanese Utility Model Publication No. JP-U-58-178435, or Japanese Patent Laid-Open Publication No. JP-A-2000-104584.
Such air conditioning devices are provided with an internal air duct that intakes air from a passenger compartment, and an external air duct that intakes air from outside of the vehicle. Air is intaken from at least one of these air ducts for air conditioning. In addition, once a temperature of this intaken air has been regulated by a heater core or an evaporator of the air conditioning device, the temperature regulated air is supplied to the passenger compartment by a blower. This allows a temperature of the passenger compartment to reach a required temperature.
However, with this air conditioning device, when heating of the heater core or cooling of the evaporator is executed with a motor of the vehicle as a driving source, temperature regulation of the intaken air for air conditioning ceases to occur along with stopping of the motor. In this state, the supply of temperature regulated air to the passenger compartment for making the temperature of the passenger compartment the required temperature ceases. Accordingly, the temperature within the passenger compartment deviates from the required value.
Moreover, it is conceivable that the heating of the heater core or the cooling of the evaporator could be executed by a driving source that is separate from the motor, when the motor is stopped. However, in the case that an output of such a separate driving source were lower than an output of the motor, the temperature regulation of the intaken air for air conditioning would be inadequate. As a result, even if the heating of the heater core or the cooling of the evaporator were executed using a separate driving source when the motor is stopped, it would not necessarily be possible to maintain the temperature within the passenger compartment at the required value. If the output of the separate driving source were to be insufficient, the temperature within the passenger compartment would deviate from the required value in the same manner as above.
In this way, in the case that heating of the heater core and cooling of the evaporator cease when the motor is stopped, and in the case that heating and cooling is executed by a separate driving source from the motor, the air condition within the passenger compartment deviates from the required condition (the temperature, and the like). In addition, discomfort of an occupant resulting from deviation of the air condition within the passenger compartment from the required condition is also an important consideration.
It is an object of the invention to provide a vehicular air conditioning device and a control method thereof that can inhibit an air condition of a passenger compartment from becoming a cause of discomfort for an occupant, as the air condition of the passenger compartment of the vehicle deviates from a required condition.
According to a first aspect of the invention, an air conditioning device for a vehicle includes an internal air duct that intakes air from a passenger compartment and an external air duct that intakes air from outside of the vehicle. This air conditioning devices intakes air for use in air conditioning of the passenger compartment from at least one of the internal air duct and the external air duct. Further, the air conditioning device is provided with a temperature regulation device, a change device and a controller. The temperature regulation device regulates a temperature of the air intaken for air conditioning from at least one of the internal air duct and the external air duct. The change device changes a respective air flow area of at least one of the internal air duct and the external air duct. The controller controls the change device such that, when a motor mounted in the vehicle is stopped, an air condition within the passenger compartment becomes less liable to deviate from a required condition.
As a result of the above configuration, when the motor is stopped, the air flow area of at least one of the internal air duct and the external air duct is changed such that the air condition within the passenger compartment becomes less liable to deviate from the required condition. As a result, on occasions when the motor stops, it is possible to inhibit the air condition of the passenger compartment from becoming unpleasant for an occupant, due to the air condition within the passenger compartment deviating from the required condition.
It should be noted that, examples of the air condition within the passenger compartment include a temperature and a humidity within the passenger compartment. Moreover, the control of the change device by the controller when the motor is stopped may be executed during at least one of a time prior to the motor stopping, a time during a stopping process, and a time after the motor has stopped. In addition, as the temperature regulation device, various devices can be suggested. For example, a device that operates with the motor as a driving source; a device that operates using a driving source separate to the motor; or a device that uses the motor as a driving source, as well as using a separate driving source when the motor is stopped may be adopted.
According to the first aspect of the invention, it may be possible for the controller to control the change device such that the air condition within the passenger compartment more easily changes toward the required condition, when the motor starts.
As a result of this configuration, when the motor starts, the air flow area of at least one of the internal air duct and the external air duct is changed such that the air condition within the passenger compartment more easily changes toward the required condition. Due to this, it is possible to inhibit the air condition within the passenger compartment from becoming unpleasant for the occupant, as a result of the air condition within the passenger compartment deviating from the required condition when the motor starts.
Further, the motor in this case may be a motor that automatically stops and restarts in accordance with an operation state of the vehicle. Moreover, the control of the change device by the controller when the motor restarts, may be executed during at least one of a time prior to the motor starting, a time during a start process, and a time after the motor has started.
According to the above aspect, the controller may be able to control the change device such that when the motor of the vehicle stops, the air flow area of the external air duct becomes small.
As a result of this configuration, it is possible to control the supply of air intaken from the outside of the vehicle to the passenger compartment via the external air duct. Accordingly, it is possible to inhibit deviation of the temperature within the passenger compartment from the required value due to this intaken air.
Moreover, from the point of view of inhibiting deviation of the temperature within the passenger compartment from the required value, it is preferable that the air flow area of the external air duct is changed so as to be substantially zero when the motor of the vehicle stops.
According to the above aspect, the controller may be able to control the change device such that the air flow area of the internal air duct becomes large when the motor of the vehicle stops.
As a result of this configuration, when the motor stops, among the air that is supplied to the passenger compartment, a proportion of the air that is intaken from the passenger compartment increases, and a proportion of the air that only circulates within the vehicle increases. In addition, as a result of regulation of the temperature of the air that only circulates within the vehicle by the temperature regulation device, it becomes easier to more effectively inhibit deviation of the temperature within the passenger compartment from the required value, along with stopping of the motor.
Moreover, from the point of view of maintaining the temperature within the passenger compartment, it is preferable that in the case that air intaken via the internal air duct for air conditioning is temperature regulated by the temperature regulator, the air flow area of the internal air duct is changed to a maximum value, when the motor of the vehicle stops.
According to the above aspect, the temperature regulation device may be a device that operates even when the motor is stopped. Further, the controller may be able to execute control of the change device based on a condition that one of a cooling requirement and a heating requirement of the passenger compartment is high.
As a result of this configuration, when the motor stops, it is possible to prevent the respective area flow areas of the internal air duct and the external air duct from being changed unnecessarily by the change device.
According to the above aspect, the temperature regulation device may be a device that does not operate when the motor is stopped. Moreover, the controller may control the change device such that, when the temperature regulation device stops operating along with stopping of the motor, the air flow area of the external air duct becomes large at the same time as the air flow area of the internal duct becomes small, based on a condition that the temperature within the passenger compartment is both higher than a required value and higher than a temperature of the air outside the vehicle.
In a state in which the temperature of the air within the passenger compartment is both higher than the required value and higher than the temperature of the air outside the vehicle, the temperature of the air outside of the vehicle is closer to the required value than the temperature of the air within the passenger compartment. According to the aforementioned configuration, when this state exists, the air flow area of the external air duct is increased, at the same time as the air flow area of the internal air duct is reduced. As a result, it becomes easier to supply air from the outside of the vehicle to the passenger compartment, and thus it becomes easier to inhibit deviation of the temperature within the passenger compartment from the required value.
According to the aforementioned aspect, the temperature regulation device may be a device that operates when the motor stops or when the motor starts. Further, on occasions when the change device is controlled by the controller along with when the motor stops or when the motor starts, it is possible for temperature regulation of the air for air conditioning to be executed such that the temperature of the air supplied to the passenger compartment does not fluctuate.
Along with control of the change device, the proportion of air from the internal air duct and the proportion of the air from the external air duct among the air for air conditioning change. As a result, the temperature of the air for air conditioning supplied to the passenger compartment becomes more liable to fluctuate. However, according to the above configuration, the temperature of the air for air conditioning is temperature regulated by the temperature regulation device such that fluctuations do not occur in the temperature of the air in this way. As a result, it is possible to prevent the occupant from feeling a sense of displeasure as a result of fluctuations in the temperature of the air.
According to the above aspect, it is possible to provide an air supply unit that executes supply of air to the passenger compartment such that, when the change device is controlled by the controller, an amount of the air supplied to the passenger compartment does not fluctuate along with this control.
When the proportion of air from the internal air duct and the proportion of the air from the external air duct among the air for air conditioning change along with control of the change device, the amount of the air for air conditioning supplied to the passenger compartment becomes more liable to fluctuate. However, according to the above configuration, the amount of the air for air conditioning supplied to the passenger compartment is regulated by the air supply unit such that fluctuations do not occur in the amount of the air in this way. As a result, it is possible to prevent the occupant from feeling a sense of displeasure due to fluctuations in the amount of air.
According to a second aspect of the invention, a control method is provided for an air conditioning device for a vehicle having an internal air duct that intakes air of a passenger compartment, an external air duct that intakes air from outside of the vehicle, a temperature regulation device that regulates a temperature of air intaken for air conditioning from the internal air duct or the external air duct, and a change device that changes a respective air flow area of the internal air duct or the external air duct. This control method includes the step of controlling the change device such that, when a motor mounted in the vehicle is stopped, an air condition within the passenger compartment becomes less liable to deviate from a required condition.